1. Field
Embodiments of the disclosure generally relate to methods and apparatus for conditioning ammunition cartridge cases. More specifically, embodiments described herein relate to methods and apparatus for sizing ammunition cartridge cases in a reloading operation.
2. Description of the Related Art
An ammunition cartridge case is typically made from a metallic material, such as steel, aluminum or brass, and includes a mouth that holds a projectile that may be fired from a firearm. Metallic cartridge cases expand as a result of the firing process. If a user desires to reuse (i.e., reload) the cartridge case, the proper cartridge case length and mouth diameter must be restored through a sizing process.
Properly sizing the metallic material includes resizing or swaging the cartridge case using a metallic die. The die is used to reform the cartridge case to proper dimensions, which were distorted by the high pressures generated during a previous firing. When the cartridge case is resized, the diameter of the mouth is reduced slightly so the case may then be reinserted into a chamber of a firearm without interference. However, while the swaging process reduces the diameter of the case along its main axis, the material is displaced axially along the length of the cartridge case. Proper sizing also includes trimming the cartridge case to the proper length for a specific chamber size for a specific caliber, and properly deburring/chamfering the cartridge case. If the case is longer than the maximum case length for the specific chamber, the neck of the case may actually extend at least partially into the throat portion of the chamber. The extension of the case into the throat may cause “pinching” of the bullet or severely increase neck tension. This may result in abnormally high or even dangerous pressures within the firearm when the reloaded ammunition cartridge case is fired.
Commercially available handheld trimming devices typically only reduce the length of the cartridge case using an end mill or other flat-ended cutting device. The trimming operation performed by the conventional devices leaves the end of the cartridge case flat but often produces burrs along the cut surface of the mouth, which requires a subsequent deburring and/or a chamfering process by another tool or tools.
What is needed is a compact cartridge case trimmer that performs a trimming and deburring and/or chamfering operation in a sizing process.